1. Field of the Invention
This invention relates generally to liquid crystal displays wherein a liquid crystal panel device, which comprises a pair of transparent plates for sealing holding a liquid crystal therebetween, is retained by a fixing frame. More specifically, the present invention relates to a liquid crystal display of the type which incorporates a back lighter for illuminating a liquid crystal panel device from behind.
2. Description of the Prior Art
As is well known, back-light type liquid crystal displays are widely used in portable word processors or computers. Obviously, this type of liquid crystal display should be as thin as possible in order to reduce overall size and weight. Thus, various attempts have been made to reduce the thickness of the display.
FIGS. 11 through 15 of the accompanying drawings show an example of prior art back-light type liquid crystal display which has resulted from such an attempt.
As shown in FIGS. 11 through 15, the prior art display comprises a fixing frame 1 having a front wall la formed with a display window 1b. The fixing frame also has a rectangularly annular peripheral wall 1c formed with engaging pawls 1d. The frame accommodates a liquid crystal panel device 2 with a set of elastic buffer strips 3a, 3b, 3c interposed between the front wall 1a and the panel device 2. The frame further accommodates a back lighter 4 behind the panel device with another set of elastic buffer strips 5a, 5b, 5c interposed between the panel device and the back lighter A third set of elastic buffer strips 7a, 7b, 7c are interposed between the back lighter and a rear lid 6, and the engaging pawls 1d are inwardly bent to engage the lid (FIGS. 14 and 15) for fixedly retaining the panel device and the back lighter relative to the fixing frame.
The panel device 2 comprises front and rear transparent plates 2a, 2b between which a liquid crystal (not shown) is sealingly held. The panel device further includes circuit boards 2c, 2d, 2e bonded respectively via film-like connectors 2f, 2g, 2h. The circuit boards carry electronic components (not shown) for driving the display.
The back lighter 4 includes a flat light guide consisting of a transparent plate 4a and a light shielding layer 4c formed on the rear surface of the transparent plate. The back lighter further includes a pair of fluorescent lamps 4b arranged at two sides of the light guide.
With the prior art arrangement described above, each fluorescent lamp 4b has a central axis coinciding with the thickness center of the light guide, so that the lamp projects beyond the rear surface of the light guide when the diameter D (see FIG. 15) of the lamp is larger than the thickness of the light guide. Further, the lamp 4b is located inwardly of the marginal portion of the panel device 2. Thus, even if the thickness of the light guide is rendered small, the panel device 2 must be spaced from the rear lid 6 at least by a distance which is larger than the diameter D of the lamp. As a result, the overall thickness H of the display is inevitably increased, and the weight of the display is also increased correspondingly.